DE19622233A1 - Torque-dependent powershift transmission - Google Patents

Abstract

Turbo boost and engine speed signals are used to estimate the engine load based on empirical data stored in the transmission controller's memory, and a percentage load is computed therefrom. The percentage load is then used to generate an appropriate duty cycle and time value for a pulse-width-modulated shift signal which controls the modulation of an on-coming directional clutch into engagement at a desired rate of engagement dependent upon the load being experienced by the vehicle. The engine load is preferably determined by linear interpolation in look-up tables of engine load versus turbo boost pressure and engine speed.

Description

The invention relates generally to electronically controlled Power shift transmission for large agricultural vehicles and more specifically on devices and methods for switching the Translation of an agricultural vehicle or earth moving vehicle by controlling the engagement of a plurality of proportional controllable clutches in coordination with the the vehicle's load as it comes from the engine speed and that developed by a turbocharger associated with the engine Boost pressure is determined.

Electronically controlled powershift transmissions are used at under a wide variety of off-road vehicles used by the great farmer commercial vehicles, such as tractors, and construction vehicles, such as Include bulldozers, road planers, and flat excavators, but not are limited to this. These gears typically have  a plurality of clutches that gradually engage can be brought, as well as a plurality of "on-off" clutch lungs that cannot be controlled proportionally. Such Transmissions also typically see a plurality of forward translations as well as a plurality of reverse translations in front. On a shift between any forward or Reverse gears or between idle and a forward or Reverse gear is typically the intervention of several Combinations of proportionally controllable directional clutches and the on-off clutches involved to get the one you want To get forward or reverse gear ratio. The Vehicles are subject to a wide range of loads the heavy-duty field conditions when using a Additional equipment, partial load conditions, as with partially in the Ground engaging devices and rolling when used Include equipment, and light load transportation conditions. The Vehicles are also subject to a wide range of Gasbe conditions, including partial throttle and full throttle. Often one electronic circuit control used to the current Driver signals for such a proportionally controllable coupling to produce lungs. Examples of such controls are in the U.S. Patents 4,855,913 and 4,425,620.

The big agricultural vehicles or earth moving engines associated with vehicles also frequently use one Turbocharger. As is known, turbochargers work by exhaust gases are supplied to them via an exhaust pipe of the engine and by using the exhaust gases to drive a turbine in a lei power input range can be used. The power input area is connected to a power output area, the also has a turbine which is provided Intake ambient air into the turbocharger. The sucked in Ambient air is led into the intake pipe of the engine and then fed to the individual cylinders. The performance input range and power output range are such coupled to each other that the two turbines are always in sync circulate. With increasing engine speed, the current increases  tion speed of the exhaust gases generated, whereby the Turbocharger for drawing in a large amount of ambient air is caused and therefore a larger boost pressure in the Intake pipe developed. Because the boost pressure is almost as fast The boost pressure indicates how the developed engine torque increases even a very good estimate of the torque at all times again that the engine is developing at the same moment. Since that Engine torque basically depends on the Engine acting load increases, gives that from the turbocharger developed boost pressure at all times a very good approximation of the current engine torque and thus that of the vehicle acting load again.

Determining the load under which the vehicle is operating before a switching operation is performed for certain switching processes important in which proportionally controllable clutches be engaged to complete the switching process. This is because the load on the vehicle is the Speed affected by the switching process should be led. For example, if the vehicle is small is loaded, a quick shift, which is a very fast Actuation of the relevant proportionally controllable direction clutch in its full engagement cause the vehicle to jerk noticeably when shifting process is completed. This is stressful not only for those internal components of the powershift transmission, but also for the components of the drive train of the vehicle. Furthermore may be due to a switching process that is carried out too quickly the jerking caused by operator fatigue, if the vehicle is operated for a longer period in which frequent switching is required.

In contrast, if the vehicle is heavily loaded, if a shift is triggered by the operator, the vehicle lose speed almost immediately, which is noticeable cause instantaneous jerk when an opening proportional clutch disengages,  while a proportionally controlled clutch to be closed is gradually brought into full engagement. These conditions also stress the internal components of the transmission and the components of the drive train of the Vehicle. In addition, the speed of the vehicle and / or the engine torque during the period between from the engagement of the clutch to be opened and the full Engagement of the closing clutch drop significantly, see above that a drop in engine torque below the peak is caused.

Therefore, it is highly desirable to change the proportions tionally controllable clutch that during a shift from one aisle to the next the load on the vehicle and so on the engine in the Moment immediately before the switching process is carried out, vote. If the vehicle is under no load conditions works, the proportionally controllable clutch should be preferred wisely engaged with a slower intervention rate be to achieve a smooth switching process and a Avoid jerking of the vehicle when shifting is executed. If the vehicle is heavily loaded, should the controllable clutch engaged much faster are considered to be under no-load conditions to sudden speed decrease of the vehicle during the switching process prevent. In addition, it would be preferred to be proportional controllable clutch engaging at a rate bring that lies somewhere between the one that is Zero load conditions would be used, and those would be used for full load conditions so the rate with the clutch is brought into engagement, if possible to precisely match the estimated load on the engine acts.

While modern drive systems use different sensors, to the operating conditions of the engine and the transmission be right, it is currently difficult to directly increase the engine load  measure up. Therefore it is necessary to know the engine load from known To determine engine operating conditions. It's a happy one representative method for determining the engine load from a turbocharger associated with the engine developed boost pressure monitor and approximate engine load from empirical data to estimate d. H. quasi the engine load as a function of To determine boost pressure. The empirical data come from Tests in which the engine torque and the boost pressure are below certain gas conditions can be measured, typically at Full throttle or wide open throttle. Using this Technology can have an accurate engine torque and accordingly An engine load can be determined when the engine is at full throttle is working. However, if the engine is under less than full throttle, i.e. H. under partial gas, this technique estimates the approximate Engine load does not exactly decrease, resulting in an uncoordinated Switching operation, as described above, leads.

It is therefore the main object of the present invention Method and device for controlling the switching operations a powershift gearbox depending on the on the engine provide acting load to abge in this way correct switching operations between the different translations of the transmission over the full range of engine load and ensure the gas conditions.

It is a further object of the present invention to provide a method and an apparatus for Monitor the speed of an engine and that of the engine assigned turbocharger developed boost pressure at a agricultural vehicle serve to the identified Engine speed and the determined boost pressure for estimation the one requested on the engine right before the start of Switching load and to use the Intervention rate of a proportional controllable clutch control how it is required to meet the requested Gear shift with an estimated engine load coordinated intervention rate.  

It is still another object of the present invention such a method and such a device for control the intervention of a proportional controllable clutch Power shift transmission of an agricultural vehicle provide that if a proportionally controllable Directional clutch when performing a shift is involved, the directional clutch with an engagement rate in Is engaged, which is dependent on the load that is on the vehicle immediately before the shift is initiated acts.

The above and other tasks are accomplished through the procedures and Devices of the present invention for monitoring the Engine speed and that of a turbocharger of an engine Vehicle developed boost pressure and to control the load manual transmission of the vehicle depending on the festge set engine speed and the determined boost pressure solved. The procedure basically includes: monitoring engine rotation number; Generating an engine speed signal; Monitor the of a boost pressure developed for the engine and generating a corresponding boost pressure signal. The engine speed signal and the boost pressure signal to the generated Related motor torque, which in turn to any time in relation to that acting on the motor Load stands. The engine speed signal and the boost pressure signal are used to get the engine torque from a given 3-D speed table to estimate the engine torque as Function that includes engine speed and boost pressure information which is in a memory of the powershift transmission associated electronic control are stored. The Estimated engine torque is used to generate a To determine engine load value from which a desirable Switching control profile can be determined. The wished Switching control profile is designed such that it is the control a closing, proportionally controllable clutch, which is engaged during the switching process, so can cause the clutch with a predetermined engagement  rate depending on the engine developed Torque is engaged so as to shift to carry out any jerking, jerking or sudden Changes in the acceleration of the vehicle caused.

In the preferred embodiment, the boost pressure signal modified to vehicle by a calibration constant to compensate for specific properties, causing deviations of the boost pressure sensor readings eliminated by Tolerances as well as the hardware of the control of the transmission Boost pressure sensor and the engine are caused. So that becomes a normalized boost pressure signal generated, which in connection with the engine speed signal used to drive an engine to determine the load value from the 3-D torque data table. So the engine load value takes into account changes in engine load due to partial gas.

In the preferred method, the engine load value becomes one stored full load value and a zero load value in Relationship set to the percentage of full load determine at which the engine is operating, d. H. a percentage Load. If the engine load value is at or below the specified one No-load value is that for the throttle opened wide engine is working without the action of an external load a pulse width modulated ("PWM") signal is generated according to one predetermined no-load duty cycle and a predetermined No-load time value for the directional clutch to be closed engaged within the predetermined no-load period bring. If the engine load value is above the specified one Full load value is below that for the throttle under wide open When the engine is running at full load, a PWM driver signal is generated with a given full load duty cycle for one predetermined full load time value is generated to close the Directional coupling with a specified engagement rate in Bring intervention.

If the engine load value is between the specified no-load value  and the specified full load value, the percentage Last used to determine the PWM duty cycle and time value that the Full-load switching control profiles are assigned linearly scale so that the driven coming directional clutch with an intervention rate and within a period of time brought, each of which is a percentage of the values which would be used to perform a full load shift to execute. The percentage load varies the switching profile according to the partial load conditions.

The various advantages of the present invention will be appreciated Specialist in reading the following description and the beige added claims, taking into account the following Drawings become clear in which:

Fig. 1 is a simplified block diagram of a boost pressure control system according to the present invention;

Fig. 2 is a flowchart explaining the calibration procedure which is used to determine the boost pressure under full load and no load conditions;

Fig. 3 is a flowchart of a calibration procedure, which is used to obtain specific vehicle to a calibration constant which is added to the charge pressure signal added to compensate for the differences in the boost pressure from vehicle to vehicle;

Fig. 4 is a simplified flowchart of the steps performed in the preferred method according to the invention, showing the optional step of monitoring the engine speed and generating the engine speed signal, by which the measured boost pressure can be further modified to reduce the boost pressure compensate if the engine speed drops because the engine is stalled by an excessive load;

Figure 5 is a flowchart of the main loop of the software program used to implement the preferred method of the present invention;

Fig. 6 is a flowchart of an interrupt routine used to read the channels of the analog-to-digital converter and to check the solenoids of the transmission for shorted windings;

Fig. 7 is a flow chart of the steps provided for checking the solenoid windings for faults and generating the driver output for the solenoid windings that need to be energized at a given time;

. 8A + 8B are flow charts of a routine on the basis of Figures 16 ms, which show the various operations which are carried out to the various sensors of the arrangement of Figure 1 to check.

. 9 is a flowchart of the charging pressure is processing routine Fig who ned be conditioned for determining a boost pressure or compensated value is used which is taken into the engine speed of the vehicle taken into;

. 9A is a flow chart of the charging Fig printing routine, which serves an engine load value as a function of the normalized load pressure signal and the engine speed signal for determining;

FIG. 10 is an exemplary listing of the boost pressure is reinforcing factors that can be applied at different engine speeds to the descending charge pressure balance, stepping on to be when the engine starts in response to an external load, stalled;

FIG. 10A is a representative 3-D torque chart depicting a sparse data set consisting of raw empirical data obtained from an engine dynamics test stand developed in accordance with the method of the present invention;

Figure 10B is a representative 3-D torque chart that represents a more fully populated data set developed in accordance with the method of the present invention, with the raw empirical data interpolated and smoothed into a form such that the controller uses this data to determine the Can use engine load value from boost pressure and engine speed;

FIG. 11A + 11B are flow charts of the steps that are carried out in the shift control routine of the present invention;

Fig. 12 is a flowchart showing the steps performed in the shifting profile routine used to determine the appropriate PWM duty cycle and time period for the percentage of full load applied to the engine when a switching operation is carried out in which the directional clutch F1 or F2 is involved.

Fig. 13 is a detailed flow chart of the charging pressure is kalibrierunterroutine described in simplified form in Fig. 3 and which is used to determine a boost-pressure charge value for generating a normalized charge pressure value to differences from vehicle to vehicle the measured values of to compensate for the boost pressure sensor;

Fig. 14 is a pair of pressure versus time plots for clutches F1 and F2 that represent the rate of engagement of these two clutches under no-load conditions;

Figure 15 is a plot of pressure versus time used to drive directional clutches F1 and F2, showing the respective engagement rates under full load conditions;

Figure 16 is a plot of pressure versus time applied to clutch F2 while shifting up from gear 10 F to gear 11 F under zero load conditions;

Fig. 17 is a plot of pressure versus time applied to clutch F2 while shifting up from gear 17 F to gear 18 F under no load conditions;

Figure 18 is a plot of pressure versus time applied to clutch F2 while downshifting from gear 11 F to gear 10 F under no load conditions, and

Fig. 19 is a plot of pressure versus time applied to clutch F2 while shifting down from gear 18 F to gear 17 F under no load conditions.

In Fig. 1 is a simplified block diagram is shown of an electrochemical African transmission control arrangement that can be used in connection with the preferred method of the present invention. The arrangement 10 basically comprises an electronic controller 12 with an internal analog-digital (A / D) converter 14 , a random access memory (RAM) 16 and an internal, electrically erasable and programmable read-only memory (EEPROM) 18 .

A boost pressure sensor 20 is connected to an input of the controller 12 , as is a conventional engine speed sensor 22 . The boost pressure sensor 20 is used to measure the boost pressure developed by a turbocharger associated with the engine 19 of the vehicle, and preferably generates 1.5 volts at 100 kPa and 3.5 volts at 200 kPa. The engine speed sensor 22 is preferably a magnetic (VRMP) sensor that monitors a gear on the input shaft of a powershift transmission 23 , the speed of which is representative of the input shaft of the powershift transmission 23 of the vehicle. In the preferred embodiment, the VRMP sensor 22 monitors a gear with 42 equally spaced teeth. The controller 12 divides the signal generated by the sensor 22 by a factor 16, so that the controller 12 receives a signal with 2,625 pulses per revolution. This gives a signal at which about 0.04375 Hz 1 rpm. correspond. An output shaft speed sensor 41 is also provided, which is also in the form of a VRMP type sensor. This sensor preferably monitors the speed of a gearwheel with 72 teeth that are approximately equally spaced and provides a signal at which 1.2 Hz corresponds to 1 rpm. Optionally, a sensor for the actual speed over the ground, for example a radar device 40 , can be provided in order to have an indication of the true speed of the vehicle above the ground.

The arrangement 10 preferably further comprises a sensor 26 for the position of an external fine clutch pedal 26 A, a clutch up position switch 27 A, a clutch pedal position switch 27 B, an idle registration sensor 28 , a display and input device 29 which is arranged in the interior of the vehicle, and means provided for modifying the drive signal (hereinafter denoted by the reference numeral 34 and referred to as valve MC1 34) for driving a proportional valve MC1, which is associated with F1 one-way clutch, and a proportional valve MC2 (the reference numeral 25 and referred to as valve MC2 35 ), which is assigned to a directional clutch F2, is used to compensate for various operating temperatures which affect the operation of the valves MC1 34 and MC2 35 . For example, at a first temperature T 1, a 50% duty cycle may be required to properly position valve MC1 34 . At a second temperature T₂₁ which is greater than T₁, however, a duty cycle of 67% may be required to positio nate the valve MC1 34 . Therefore, means for modifying the drive signal are provided in order to compensate for the above-described variations in the properties of the valves MC1 34 and MC2 35 due to temperature differences. The controller 12 continues to respond to a shift control lever 36 for selecting the various ratios of the powershift transmission 23 and the basic direction of work (ie either forward or reverse).

A specific means for modifying the driver signal includes a temperature sensor 30 for measuring the coil temperature of the valve MC1 34 . While the temperature sensor 30 is preferably a thermistor, any device that provides a voltage signal indicative of the coil temperature of the valve MC1 34 can be suitably used in the present invention. The coil temperature of valve MC2 35 can be considered equal to that of valve MC1 34 , or alternatively a second temperature sensor can be used to measure the coil temperature of valve MC2 35 . The drive signals for driving the valves MC1 34 and MC2 35 are compensated for using these temperature values.

Another means for modifying the drive signal includes a temperature sensor for measuring the temperature of the hydraulic fluid flowing through valve MC1 34 and a current measuring sensor for determining the electrical current flowing through the coil of valve MC1 34 ; this combination is indicated by reference number 30 . While the temperature sensor 30 is preferably a thermistor, any device that outputs a voltage signal indicative of the temperature of the hydraulic fluid flowing through the valve MC1 34 can be suitably used in the present invention. Also, while the current measuring device 30 is preferably an ammeter connected between the high voltage side of the coil of the valve MC1 34 and ground, any device that outputs a voltage signal indicative of the current through the coil of the valve MC1 34 can be suitably used in the present invention. The temperature of the flowing through the valve 35 MC2 hydraulic fluid and the current flowing through the coil of the valve MC2 current 35 can be identical as viewed with those measured for MC1 34, or they may be measured with independent sensors. The driver signals used to control the MC1 34 and MC2 35 valves are compensated for using these temperature and current values.

In the preferred embodiment, controller 12 is a Motorola 68HC11E1 microprocessor that is operated in extended mode. For illustrative purposes only, the method of the present invention will be described with reference to a "Funk 9400" powershift transmission manufactured by Funk Corp. of Coffeyville, Kansas. This special model of the transmission has 18 forward and 9 reverse gear ratios, which are selected by activating combinations of hydraulic clutches via electromagnetic control. The clutches are divided into three groups of three clutches, which are referred to as number clutches 1 , 2 and 3 , letter clutches A, B and C and directional clutches F1, F2 and R. The desired transmission ratio is selected from each group by the engagement of a clutch. The directional clutches F1 and F2 are always involved when a shift from gear 9 F to 10 F or from gear 10 F to gear 9 F is requested. The directional clutch R is involved when shifting from idle to any reverse gear. Clutch F1 is involved when shifting from idle to gears 1 F through 9 F. The clutch F2 is involved when shifting into one of the gears 10 F to 18 F.

Each of the nine clutches also has an "on / off" electromagnet which allows the clutch to engage when voltage is applied. The valves MC1 34 and MC2 35 , which are shown in simplified form in FIG. 1, are used to control the pressure on the directional clutches F1, F2 and R. The valve MC1 34 controls the pressure on the directional clutch F1, while the proportionally controllable valve MC2 35 both the pressure on the directional clutch F2 and the directional clutch R. The valves MC1 34 and MC2 35 cause a decreasing clutch pressure and with increasing current are ideally suited for use with pulse width modulated (PWM) current drive signals generated by controller 12 . In other words, if the duty cycle of the drive signal for one of the valves MC1 34 or MC2 35 is extended, this causes a decrease in hydraulic pressure which enables the diaphragm springs associated with the directional clutch to force the clutch into engagement. The presently preferred embodiments do not consider varying the engagement rate of the R (reverse) directional clutch in a controlled manner, as is the case with the directional clutches F1 and F2. However, it is too clear that the teaching given here could easily be used by any person skilled in the art to vary the engagement rate of the directional clutch R if desired for a particular application.

Determination of a full-load and no-load switching control profile

The preferred methods according to the present invention include the use of predetermined shift control profiles for zero load and full load shifts. The zero-load and full-load shift control profiles each represent a "pressure over time" shift profile which is intended to engage the clutch to be engaged with a predetermined engagement rate. The full-load and zero-load switching control profiles are used by controller 12 to generate PWM drive signals, each of which has an appropriate duty cycle for an appropriate duration to produce the desired "pressure over time" switching profile. Accordingly, if, for example, a full load shift is desired, the controller 12 generates a PWM signal for a desired duration with a duty cycle sufficient to close the directional clutch to be closed (ie clutch F1 or F2) at the desired engagement rate To engage to achieve the predetermined full load "pressure over time" curve. In other words, the PWM signal controls the rate at which the driven proportional solenoid valve (ie, either valve MC1 or MC2) is opened for a predetermined, predetermined time interval in order to carry out the full-load switching operation.

In Fig. 2 the steps are shown that are used to set the full-load and no-load switching control profile. As indicated by reference to a "predetermined" profile, these steps are preferably performed once during the development of the transmission. The full fast and zero load shift control profiles are then stored in a memory of the controller 12 for use as described below. Initially, the vehicle is propelled on a flat surface, and preferably on a concrete surface, to minimize the drag on the vehicle until a full throttle condition is reached, as indicated by step 44. Next, the boost pressure detection (ie, the boost pressure value) from the boost pressure sensor 20 and the engine speed from the engine speed sensor 22 are recorded under no-load conditions, as indicated by step 46. At step 48, the appropriate no-load shift control profile is determined to determine a desired engagement rate for any of the directional clutches when a shift under no-load conditions is requested. This is determined by trying out different values for the duty cycle and its duration until a combination is found that creates the right "feel" for a shift under no-load conditions. As already mentioned, such a switching operation is one that is carried out quickly, but without jerking or jerking the vehicle.

As further shown in Fig. 2, a tensile load is then attached to the vehicle that is sufficient to reduce the engine speed at full throttle to a nominal speed in the respective engine. It is clear that the nominal speed of an engine is the engine speed at which the engine develops its maximum torque. This procedure is indicated by a step 50. At step 52, the boost pressure from the boost pressure sensor 20 and the engine speed from the engine speed sensor 22 are recorded, which reflect the boost pressure value and the engine speed value under full load conditions. Next, as indicated at step 54, an appropriate shift control profile curve (ie, pressure versus time curve) is determined to produce a desired engagement rate for a shift operation performed under full load conditions. More specifically, a suitable duty cycle and time interval are determined by repeated trial and error which engage the clutch to be engaged with an engagement rate and within a desired time. This intervention rate and time interval are designed to cause a shift that is fast enough to prevent a noticeable drop in engine speed while the shift is being performed, so as to produce a smooth shift without a sudden decrease in vehicle speed .

When partial load conditions (ie conditions somewhere between zero load and full load) act on the vehicle engine, the pressure-over-time switching control profile is modified (ie reduced) with the percentage of the full load, as reduced by one engine load approximation techniques described below. For example, if the estimated engine load is approximately 50% of the full load, the PWM duty cycle is modified by the controller 12 to generate a pressure-over-time switching control profile that includes the directional clutch to be engaged with an engagement rate and for one engages an appropriate amount of time that is about 50% of the rate at which it would intervene under full load conditions, or about half the predetermined full load time period. Accordingly, if the engine load value was approximately 75% of the full load, a duty cycle was generated that engages the respective clutch to be engaged at an engagement rate and for a period of time that is approximately 75% of the rate or period of time under full - Load switching conditions were applied.

From the above it can be seen that the boost pressures and engine speeds under full load and No-load conditions are determined, the load under which the engine works at any time from the current boost pressure and the current engine speed can be estimated, which then as Percentage of full load is expressed. The estimated Motor load can be used to get a very good approximation the current load under which the engine is operating, and therefore also to provide the speed of a shift that should be adhered to to avoid unwanted vehicle jerks or - jerk as well as sudden changes in acceleration avoid. It should be noted that the quality of a Switching operation, d. H. whether a shift is soft or rough, is subjective and therefore based on personal preferences. The The present invention provides means for achieving more consistently Switching operations over the range of the engine load condition from Zero load to full load based on this subjective determination ready.

Boost pressure calibration procedure

In order to improve the consistency of the switching operations under load from vehicle to vehicle, the boost pressure sensor 20 ( FIG. 1) is preferably calibrated on the respective vehicle. In Fig. 3, this procedure is presented in a simplified form as a flow chart 55 . A detailed explanation of this calibration procedure will be given in connection with the flow chart of FIG. 9. Initially, the vehicle is driven on a flat surface under full throttle and no load conditions in gear 9 F, as indicated by step 56. The boost pressure sensor 20 is then monitored for a predetermined period of time, for example and preferably for about three seconds, as indicated in step 58. During this period, a large number of measured values of the boost pressure sensor 20 are recorded. Next, an average boost pressure sensor measured value is determined from the plurality of measured values obtained in step 58, as indicated in step 60. Next, as indicated in step 62, the difference between a predetermined "baseline" boost pressure value and the mean boost pressure sensor measured value is determined, which reflects the deviation of the mean boost pressure sensor measured value from the predetermined baseline value. This difference (ie this surcharge) represents a vehicle-specific calibration constant, which takes into account deviations caused by tolerance differences in the hardware of the arrangement, in the boost pressure sensor 20 itself, the engine itself and virtually any other factor that measures the measured values of the boost pressure sensor 20 influenced, caused.

Overview of the basic function

Before describing the significant details of the individual steps which are used in the course of the preferred method according to the present invention, a simplified overview of these steps is given in FIG. 4. Initially, the controller 12 monitors the boost pressure from the boost pressure sensor 20 and generates a boost pressure signal which indicates the boost pressure developed by the turbocharger of the vehicle engine, as indicated in step 64. Next, an engine speed signal is read in from the engine speed sensor 22 ( FIG. 1), as indicated in step 66.

In a preferred method, step 66 is optional but preferred from the point of view that the boost pressure typically drops slightly when the engine is under load conditions works, the maximum torque output of the engine exceed. In other words, when the one acting on the engine Load increases, a point is reached at which the engine turns on generates maximum torque, which is also the maximum Charge pressure corresponds to that generated by the turbocharger. If the load is increased above this point, the engine speed decrease slightly, which also increases the boost pressure sinks. These are undesirable conditions because of the control  from this would conclude that on the vehicle and thus on the load acting on the engine drops, though it actually does increases as long as this situation is not compensated. This will be described in detail shortly.

In another preferred method, step 66 is off the point of view that both the boost pressure and The engine speed can also be used to increase the engine load to calculate. This other method is based on variations of the engine adjusted torque, which results from engine speed variations animals because the engine torque as a function of both the loading Pressure signal and the engine speed signal is calculated. In this way, the engine torque is based on the Operating conditions of the engine estimated more precisely.

Returning to FIG. 4, controller 12 determines whether a shift has been requested by the operator involving a directional clutch F1, F2, or R, as indicated in step 68. If no, the boost pressure signal and the engine speed signal are updated as indicated in steps 64 and 66. If so, the controller 12 determines the appropriate shift control profile based on the determined boost pressure signal and the determined engine speed signal, as indicated in step 70.

In step 70 of FIG. 4, controller 12 determines a shift profile control signal from the approximated engine load, which is estimated from the boost pressure signal and the engine speed signal. In a preferred embodiment, controller 12 conditions the boost pressure signal with an engine speed constant value that compensates for the drop in boost pressure that occurs if the engine speed begins to drop. In other words, if the engine is loaded so that the maximum torque is exceeded, (i.e. begins to fall), the determined boost pressure signal is multiplied by the engine speed constant to indicate a drop in the boost pressure signal and an incorrect indication to the Controller 12 to prevent the load on the vehicle from dropping when the load actually increases. The controller 12 then calculates an approximate engine load from the conditioned boost pressure signal that is used to determine the shift profile control signal. This is more fully described in connection with the flow chart of FIG. 9.

In another preferred method, instead of a function of the boost pressure that is conditioned based on the engine speed, an approximate engine load value is calculated directly as a function of the engine speed and the boost pressure. The calculation of the engine load value according to the other preferred method will be described more fully in connection with the flow diagram of FIG. 9A.

Finally, controller 12 generates the PWM driver signal for a suitable duration and with a suitable duty cycle for the respective directional clutch, as shown in step 72, in accordance with the shift control profile (either full load or zero load). This then has the consequence that the respective directional clutch is brought into engagement with the appropriate engagement rate as a function of the vehicle load. Thus, by determining the boost pressure developed at a given time and the engine speed of the vehicle developed at the same time, a very good approximation of the engine load can be determined, which can then be used to determine the appropriate engagement rate of a directional clutch to be closed when a shift is carried out becomes.

It is clear that this is from the conditioned boost pressure signal or engine torque calculated from the engine load value becomes as if it were pure tensile loads while it was doing mainly related to the operation of the PTO includes standing engine load. The procedure described here could easily be modified by a person skilled in the art Influence of the load on the engine via the PTO to avoid. This could easily be done if one  Appropriate torque sensor is used to measure the torque the PTO by monitoring the measured at all times PTO torque when determining the conditioned Boost pressure signal or the engine load value is taken into account. Z. B. It may not be desirable to have a quick shift to perform an operation that would normally be generated if a maximum boost pressure signal is present if it is determined that a large proportion of the engine power is used to control the PTO drive the engine, and that the vehicle with moving at a relatively slow speed. In this If so, it would be more desirable for the PWM drive signal to increase modify it to have a slower clutch engagement causes.

Detailed function

Referring to FIGS. 5 to 12, the detailed operation of the preferred method will now be discussed in accordance with the prior invention lie. In the flowchart of FIG. 5, the entire sequence of steps is shown of the soft ware are carried out, which is used to implement the method of the present invention. So is FIG. 5, a complete cycle again, which is executed by the controller 12, which is also referred to as microprocessor 12. The execution time of the steps shown in Fig. 5 rarely exceeds 4 ms and is often less than 1 ms.

The first step is to perform a reset initialization routine, as indicated in FIG. 74. Upon power up or under any other reset conditions, the microprocessor 12 registers are configured as required. The outputs of the microprocessor 12 are configured in an initial reset status. The microprocessor 12 interrupts are disabled, but the interrupt masks are configured as desired. The checksum of the operational code associated with the software of the present invention is calculated and checked to ensure that no memory errors have occurred. If the checksum is incorrect, the microprocessor does not execute any further software commands.

Still in step 74 of FIG. 5 is checked, the internal micro-processor RAM 16 and set to zero. If one of the RAM tests fails, the microprocessor 12 does not execute any further software commands. Further necessary information is obtained from the internal EEPROM 18 of the microprocessor 12 . This information includes the maximum desired forward gear (e.g. 18 if a Funk 9400 series transmission is used), vehicle specific clutch calibration values for clutches F1, F2 and R, the minimum and maximum voltage measurement values of the fine pedal position sensor 26 and the calibration values for the boost pressure sensor 20 . All error codes are also deleted. The CONFIG (configuration) register stored in the internal EEPROM of the microprocessor is checked in order to ensure correct operation of the control. If the CONFIG register is incorrect, the software of the invention tries to reprogram this register and execution of the program continues. The internal timers are configured as required and the interrupts are activated as configured. The vehicle's transmission is brought into neutral and the preselected forward and reverse gears are prepared as desired. In the preferred embodiment, the preselected forward gear is 6th gear and the preselected reverse gear is 3rd reverse gear.

In step 76 of FIG. 5, the software begins executing the main loop steps comprising steps 79-100. At step 76, the internal monitoring timer of the microprocessor 12 is activated. The operating messages of the monitoring timer are stored in two areas of the RAM, which were initialized in the reset initialization routine (step 74). The first operating byte of the watchdog timer is written into the watchdog timer at the beginning of the main loop. The second message is written in step 100 at the end of the main loop. Starting from the reset routine (step 74), there are no other activations of the monitoring timer. This ensures that the software executes the complete loop and that the time over the loop is not too long. In addition, the availability of the operating values of the monitoring timer in RAM makes it possible to recover from RAM faults by resetting the monitoring timer internally if incorrect values are written. This also ensures that the microprocessor 12 has been validly reset before the code is allowed to run. In order to increase security, the two values are preferably arranged at the end of the RAM used, so that any stack overflow in the microprocessor 12 overwrites these values and the execution of the software is stopped by the reset by the monitoring timer due to these incorrect messages.

With further reference to Fig. 5, the microprocessor 12 reads at step 78 to be the optional radar device 40 closed input that if such a device is used. This provides the microprocessor 12 with a speed signal to the true ground speed if that is desirable for any reason. However, it is clear that this step is optional and not essential for the main loop.

In step 80, the speed of the output shaft of the powershift transmission is determined by reading in the speed sensor 41 connected to the output shaft input. As previously stated, in the signal from the output shaft speed sensor, which is a VRMP sensor, corresponds to approximately 1.2 hearts 1 rpm. An approximate tire speed is calculated on the assumption that the vehicle is traveling at 1.0 mph at approximately 151.84 rpm. However, it is clear to the person skilled in the art that the wheel size influences this calculation as well as the tire wear.

At step 82, the input shaft speed is calculated and filtered. This is done by the microprocessor 12 by reading the input connected to the input shaft VRMP (ie the engine speed sensor 22 ). At step 84, a query is made as to whether a 5 ms timer that started immediately after the reset initialization routine (step 74) has expired. If so, a routine is performed on a 5 ms time basis, as indicated at step 86, before the next step of the main loop is performed. The routine on a 5 ms time basis will be described in more detail shortly. It is essential, however, that this routine include performing various diagnoses, updating the values coming from the internal A / D converter 14 of the microprocessor 12 , and checking all output drivers and solenoids for various errors.

With continued reference to FIG. 5, the software checks whether a 16 ms timer configured in the software has expired, as indicated at step 88. This timer was also started immediately after the reset initialization routine (step 74). If the 16 ms timer has expired, a routine is executed on a 16 ms time basis, as indicated by step 90. In short, this routine includes checking and updating a number of operating parameters, including the current position of switches that indicate the position of the shift lever 36 (i.e., which gear ratio and which drive direction is requested), performing engine speed compensation calculations taking into account the Engine speed compensation values, scaling the boost pressure sensor reading based on the boost pressure calibration value, and other operations. This routine will also be described in more detail shortly.

After the 16 ms timer has expired or the routine has been executed at step 90, as indicated in step 90, the digital switching inputs of the microprocessor 12 are sampled and the results are used to determine when one of the shift levers 36 assigned switch has changed its position and has stabilized, which is determined in a separate loop on a time basis. The details of this verification loop are described in U.S. Patent 5,388,476.

Next, the serial communication interface is queried by the microprocessor 12 to see whether it has received a message from an external device in communication with the microprocessor 12 . If so, the message command is processed, a message response is established, and transmission of the response is started, all at step 94. In this context, it is clear that, since it offers the possibility of serial communication, the microprocessor 12 has external development devices can be connected if it is desired to re-program any stored constants, such as the engine speed compensation values.

At step 96, a micro self diagnostic routine is performed that updates the control registers and performs various tests of the system RAM in addition to performing other routine tests of the microprocessor 12 . At step 98, the microprocessor 12 is requested to activate an external watchdog timer. Essentially, it is necessary for the microprocessor 12 to switch one of the outputs within about 16 msec to prevent the external watchdog timer from resetting the microprocessor 12 . At step 100, the second operational message is written at the end of the main loop, as previously explained.

In FIG. 6, an interrupt routine 102 is shown which is referred to as "OC5 Interrupt". This interrupt occurs every 1 ms, as indicated in step 104. Immediately after the interrupt occurs, the OC5 interrupt mark is cleared, as indicated in step 106, the channels of the internal A / D converter are read in and the results obtained are stored in the RAM 16 of the microprocessor 12 ( FIG. 1) saves, as indicated in step 108. Next, the solenoid drivers that are currently on are tested to determine if the associated solenoids are shorted, as indicated in step 110. This routine is repeated approximately 1 ms later and then every 1 ms thereafter.

FIG. 7 shows the routine 1 ms time base in greater detail, which is indicated at step 86 in FIG. 5. The first step in this routine includes checking whether a 0.5 second delay has elapsed after turning on, as indicated at step 112. If no, the routine is ended, as indicated in step 114. If the 0.5 second delay has occurred, a shift control routine is executed, as indicated in step 116. This routine essentially involves setting up and handling all of the electromagnetic shift patterns and duty cycles required to perform a shift and hold (ie, refresh) the solenoids and the duty cycles required to maintain operation in the currently selected gear. Next, as indicated at step 118, a driver diagnostic routine is run that checks whether the solenoid drivers that need to be turned on to perform a shift are actually functional (ie, not shorted or open).

Next, an output driver / coil failure subroutine executed, as indicated at step 120, any in Analyzed step 118 detected errors. The subroutine step 120 also tries to find a gear that closest to the desired gear requested by the examiner which is due to an error of an associated Component can not be used. At step 122, a Driver output routine executed that the to be switched on Appropriate currents are applied to the electromagnets  either perform a switching operation or operate in maintain a desired gear.

Routine on a 16 ms time basis

The routine on the 16 ms timebase that is executed at step 90 of the main loop shown in FIG. 5 is shown in detail in FIGS. 8A and 8B. Starting at Fig. 8A, at step 124, a turn on delay processing routine is executed to ensure that a predetermined minimum amount of time has passed since the power on, e.g. B. a 500 ms delay. At step 126, the clutch calibration values are stored in the EEPROM 18 of the microprocessor 12 for the driven clutches F1, F2 and R. These values reflect the current impact value that is required to just cause the clutch to start engaging. Next, at step 128, all vehicle specific wastegate calibration values are stored in the EEPROM 18 .

At step 128, the vehicle-specific boost pressure calibration constant (ie, the boost pressure value) that has been set, as described in connection with FIG. 3, is stored in the EEPROM 18 of the microprocessor 12 . At step 130, an EEPROM operating subroutine is executed to ensure that all values to be written to or read from the EEPROM 18 are valid.

With continued reference to FIG. 8A, in step 132 an optional calibration surcharge value for each of the actuated clutches F1, F2 and R is added to the clutch calibration values that were stored in step 126. Step 132 reproduces an optional measure by means of which additional clutch calibration information can be added in the form of an impact value, for example by trained operating technicians, in order to further modify the shifting properties of any directional clutch.

With continued reference to FIG. 8A, an on / off hold timer is incremented in step 134 that essentially monitors how long the solenoid valve coils associated with each transmission on / off clutch are held at 12 volts. It should be noted that the on / off solenoid valves each have 6 volt coils. However, a 12 volt DC signal is applied to each coil when it is turned on to very quickly bring the electromagnet into its on position. The on / off hold timer monitors how long a single solenoid valve is held at +12 volts DC. This timer is also cleared when a +12 volt DC signal is applied to one of the on / off solenoid valves for the first time. The timer is incremented approximately every 16.3 ms.

In step 136, a shift lever monitoring processing routine is executed that reads the switches that are associated with the shift lever 36 and that indicate the position of the lever 36 . This routine is described in more detail in U.S. Patent 5,388,476. However, it is clear that the routine detailed there is not essential to the proper functioning of the present invention; however, it is preferably provided at this point in routine 90 on a 16 ms time basis.

Still referring to Fig. 8A, an engine speed compensation calculation routine is executed at step 138 which modifies the duty cycle of the driven clutches F1 and F2 based on the engine speed. This compensates for the lower hydraulic pump pressure generated at lower engine speeds. At step 140, an analog filter routine is executed that filters analog voltages from the boost pressure sensor 20 , the output voltage of the fine clutch pedal sensor 26 , feedback voltages obtained from any diagnostic sensors, and the system voltage.

At step 142, an error processing routine is performed to pass errors that do not affect the output drivers for the solenoid valves. For example, this routine checks whether the fine clutch pedal sensor 26 is not short-circuited, whether the boost pressure sensor is not short-circuited, or whether the output shaft speed sensor 41 is not functioning incorrectly.

With continued reference to FIG. 8A, a shift transition mode monitoring routine is performed, as indicated at step 144, to ensure that the voltage signal from the clutch up switch 27 A is within acceptable limits, that if a signal is generated from the clutch pedal bottom position switch 27 B, this clutch pedal ground position signal is within acceptable voltage limits, and that the fine pedal potentiometer 26 ( Fig. 1) operates within valid voltage limits.

At step 146, a frequency input overflow routine is performed to set the input shaft or output shaft speed to zero if no pulses are received from the VRMP sensor associated with input sensor 22 or output sensor 41 , or if the frequency of the pulses from the respective sensor falls below a predetermined lower limit. At step 148, a boost processing routine is executed. This routine will be described in greater detail along with the flow chart of Fig. 9; it essentially involves scaling the boost pressure value provided by the boost pressure sensor 20 depending on the engine speed to compensate for a drop in boost pressure that occurs when the engine is operating at high loads that stall the engine. Alternatively, a routine can be used, as described in greater detail in connection with the flow chart of FIG. 9A, which directly calculates an engine load value from the boost pressure signal and the engine speed signal.

In step 150, a fine pedal monitoring routine is started carried out to determine the duty cycle that applies to the  Directional clutch F1 or F2, which by means of the clutch pedal brought into engagement by the operator must, in order to the clutch appropriate to the current pedal position to generate pressure. So this routine sets the appropriate one Duty cycle, that of the current clutch pedal position corresponds. At step 152, a diagnostic routine is opened short-circuited outputs carried out. This routine closes the reading of the voltages of the switched on electroma windings every 5 ms. Within a period of at least three test values are recorded every 16 ms, based on which it is determined whether the coil currently switched on is short-circuited. If any coil is shorted, their voltage falls below a predetermined lower limit. A diagnostic error message can then be displayed on a display board Vehicle supplied to indicate to the operator that a Error condition has occurred.

At step 154, shown in FIG. 8B, the software processes certain information every 1048.576 ms and performs error condition checks, which are described immediately. Step 154 checks whether 1049 ms have elapsed. If so, a routine is executed on a 1048 ms time basis. This routine generates an audible alarm signal that is present for about three seconds during the boost calibration mode. This alarm is generated in response to an operator pressing appropriate switches on the display / input device 29 for a period of longer than 3 seconds while the tractor is on a smooth, level surface and its throttle is wide open, as well as the shift lever 36 is in the idle position. The A / D measured value of the thermistor (resistor 30 , shown in Fig. 1), which indicates the temperature of the driven solenoid, is also processed, and the measured temperature is updated. The measured value of the boost pressure sensor 20 is checked for error conditions, as is that of the input shaft speed sensor 22 . The fine clutch pedal position sensor 26 is checked and the minimum and maximum calibration values are updated if necessary.

After the routine on 1048 ms time base at step 156 is executed or the test at step 154 is no checked whether at least 524 ms have elapsed, as in step 158 is indicated. If so, a routine is set to 524 ms Time base executed, as indicated in step 160. In This routine is used to measure the system values every 524.288 ms tension on the presence of overvoltages or under voltages checked. The engine speed is processed to the correct engine speed compensation value for use in Scaling the boost pressure value.

After the routine at step 160 is executed or test If no in step 158, it is checked whether at least 262 ms have expired, as indicated in step 162. If so, a routine is executed on a 262 ms time basis. At this A short-circuit diagnosis is routine every 262.144 ms ne fault lamps, the diagnosis on open solenoids and the Driver / Electromagnetic Feedback Circuit Failure Diagnostics guided. The display switch input stability routine will carried out, and if any display switch its position changed and stabilized, the corresponding one Switching transition processed. Ultimately, a clutch overload diagnosis carried out. This diagnosis includes essential checks of the input shaft speed of the Gearbox against the output shaft speed to tighten ask whether taking into account the known input shaft speed and the applied gear ratio excessive clutch grinding.

If the test in step 162 yields no or the routine is executed in step 164, it is checked whether at least 131 ms have expired, as indicated in step 166. If so, a routine is executed on a 131 ms time basis, as indicated in step 168. With this routine, the serial data stream containing the display switch information is received from the display every 131.072 ms. In any other loop, the updated display information is sent to the display. The shift lever switch failure diagnosis and the diagnosis of short-circuited output drivers are carried out. The status of a parking lock bulb is updated, as is the status of the audible alarm. The engine speed and vehicle acceleration values are calculated and the maximum duty cycles for energizing the electromagnets are calculated based on the filtered system voltage measurements. The calculated engine speed and vehicle acceleration values are used in substitute shifting by microprocessor 12 to assist in the selection of the appropriate gear that most closely matches the operator-selected gear when engaged based on engine speed acceleration and vehicle acceleration.

If the routine at step 168 is executed or the test If no in step 166, it is checked whether 66 ms have elapsed are, as indicated in step 170. If this test does If the result is yes, a routine is executed on a 66 ms time basis leads, as indicated in step 172. In this routine every 65.536 ms, the fine pedal diagnosis is carried out together with the Input and output shaft sensor diagnostics performed. As soon as this routine is executed or the test at step 170 is the If the result is no, the routine ends on a 60 ms time basis, such as is indicated at step 174.

In Fig. 9 is executed 8, the boost pressure processing routine at step 148 shown in Fig., Shown in more detail. Initially, the software determines whether the system is in the boost pressure calibration mode, as indicated at step 176. The boost pressure calibration mode is preferably initiated via a trigger arranged on the input device. If the calibration mode has been selected by the operator or an operator, the boost calibration subroutine (routine 55 of FIG. 3) is executed as indicated at step 177.

As indicated in step 178 of FIG. 9, it is checked whether the engine speed sensor 22 ( FIG. 1) is faulty. If so, it is assumed that the input shaft speed of the transmission bes is the maximum input shaft speed and is, for example, approximately 2400 rpm, as indicated in step 180. It is clear that this maximum input shaft speed value depends on the engine and / or vehicle used.

Next, the determined boost pressure value, which now, after being modified by the vehicle-specific calibration constant, represents a normalized value, is further modified by multiplying by an appropriate engine speed constant selected from a plurality. The engine speed constants are stored in a look-up table, as indicated in step 182, and compensate for situations in which the engine has started to stall, causing the boost pressure values measured by sensor 20 ( FIG. 1) to drop. As already briefly explained here, the boost pressure signal measured by the sensor 20 increases with the engine speed, this increase being regarded as linear. However, when the load on the vehicle becomes so great that the engine begins to stall, the falling engine speed leads to a decrease in the boost pressure developed by the engine's turbocharger. If this situation is not compensated for, the microprocessor 12 would erroneously determine that the load is decreasing while the load on the vehicle is actually increasing. Thus, the microprocessor 12 would determine that the vehicle is more lightly loaded and would cause the use of an unsuitable duty cycle for the PWM driver signal to drive the respective clutch in engagement. By multiplying the normalized boost pressure value by the appropriate engine speed constant, the drop in boost pressure that occurs when the engine begins to stall is compensated for. From Fig. 10 it can be seen that the multiplier for the charge pressure value rises below 2100 rpm with decreasing engine speed. In this example, 2100 rpm represents the engine speed at which the engine develops its maximum torque under full load. When an external load on the vehicle begins to stall the engine, the boost pressure multiplier increases. Referring again to FIG. 9, in step 184 the normalized boost pressure value is multiplied by an engine speed constant to obtain a conditioned or compensated boost pressure value.

The engine load estimation procedure described above gives consistent results when the engine is operated at or near full throttle conditions. In typical agricultural applications, this applies to a majority of the engine operating conditions. However, inaccuracies in engine load estimation occur when the engine is operating under partial throttle conditions. It is believed that these inaccuracies can be attributed to the non-linear slope of the change in boost pressure under partial gas conditions. Another preferred method of estimating engine load based on boost pressure and engine speed, which can take into account varying characteristics of the boost pressure over the entire range of engine operating speeds, is shown in FIG. 9A.

Referring now to FIG. 9A, the other preferred method of estimating engine load as a function of boost pressure and engine speed will now be described. Aspects of this alternative method that are similar or identical to the aspects previously described in connection with FIG. 9 are provided with the same reference symbols; the lines behind the reference numbers indicate the alternative method. So, the boost pressure processing routine, which is carried out in step 148 of FIG. 8, as shown and described in more detail by the boost pressure processing routine 148 'is replaced.

As shown in Fig. 9A, if initiated, the wastegate calibration steps 176 'and 177 ' are performed, which give a vehicle-specific calibration constant. It is also checked in step 178 whether the speed sensor 22 is functioning properly. If the sensor 22 does not function properly, a maximum input speed of 2400 rpm is then used as the default value.

During operation of the vehicle, the input speed sensor 22 and the boost pressure sensor 20 are interrogated at step 181 ', and an engine speed signal and a raw boost pressure signal are generated in the electronic controller 12 . The boost pressure raw signal is modified with the calibration constant in order to obtain a normalized boost pressure signal, as previously described. The controller 12 then calculates an estimated engine load as a first order linear function of the engine speed signal and the normalized boost pressure signal, hereinafter referred to as the engine load value. The form of this estimate is given below as equation (1).

τ = (A₁x + A₀) (B₁y + B₀) (1)

in which
τ is the estimated engine load or engine load value;
x is the boost pressure value;
y is the engine speed and
A₁, A₀, B₁, B₀ are constants.

One way to perform this calculation is to a tabular data lookup operation and data perform interpolation as in steps 182 'and 184 'are indicated.

At this point, the engine load value represents a more accurate approximation of the engine torque than the conditioned boost pressure value or the scaled boost pressure, which is reproduced in step 184 according to FIG. 9, because the variations in the boost pressure which result from partial-load conditions are taken into account more precisely are. The boost pressure processing routine 148 'is completed in step 186' and the engine load value is used in an identical manner to the conditioned or compensated boost pressure value, which was calculated according to the first procedure previously described in connection with FIG. 9. For example, a person skilled in the art will easily determine that the engine load value can directly replace the conditioned or compensated boost pressure value in the methods described below.

Referring again to FIG. 9A, the details of the data table lookup function and data interpolation of steps 182 'and 184' will be described in further details. As previously mentioned, it has been found that engine load can be more accurately approximated as a function of both engine speed and boost pressure under given operating conditions. One method of calculating this correlation is to construct a three-dimensional torque table that shows the boost pressure on the x-axis, engine speed on the y-axis, and PTO torque on the z-axis. An exemplary 3-D torque table is shown at 182 a 'in Fig. 10A. Thus, the establishment of an exact torque table is an important aspect to achieve consistent shifting across the range of engine load and gas conditions using the present invention.

A currently preferred method for setting up the torque tafel is to get experimental data from a vehicle engine win, which is connected to a dynamometer via the PTO is. With no load acting on the motor, a Gas condition set to the starting point of data collection to determine. The following is the engine with the dynamometer loaded until the engine speed drops by 50 rpm. At this The data of the boost pressure and the PTO shaft rotation become the point moments recorded. The engine is then further loaded until the engine speed drops by a further 50 rpm. This process is used for an engine speed range of 2400 to 1600 rpm  the given throttle position is repeated, from which a series of Data points results at which the engine load for a given Engine speed and a given boost pressure is known. Appropriate tests are carried out for different gas conditions closed throttle up to wide open throttle.

The method for obtaining experimental data described above gives a sparse torque table 182 a ', as shown in Fig. 10A. The thinly populated torque table 182 a 'has about 80 data points with only about 4 data points for a certain engine speed in the area in which the slope of the engine torque changes quickly, ie in the area of the maximum torque. It is currently preferred to fill in missing areas of the 3-D torque table using a first-order linear interpolation technique. More specifically, a least squares regression for four adjacent data points is preferably used to estimate intermediate values within the range defined by these four data points, as shown in equation (2) below. This step is repeated for each set of four adjacent data points to obtain a more fully populated torque table with approximately 744 data points.

One consequence of filling the missing areas of the torque table by linear estimation is the formation of anomalies or discontinuities at the edge of the interpolated data areas. So it is currently preferred to use a smoothing function along the edges to eliminate these anomalies. For example, three point floating averaging can be applied to the data, with a filtered value being calculated by averaging over three adjacent data points that have been multiplied by an appropriate weighting function. This smoothing function is first performed along the y-axis (engine speed axis) while keeping the x-values (boost pressure values) constant, and then it is performed along the x-axis (boost pressure axis) while keeping the y-values (engine speed values) constant will. A representative speed table 182 b ', which was generated using the methodology described above, is shown in Fig. 10B. This data, which is shown graphically in Fig. 10B and which is represented by the dots at the intersection of the x and y lines in Fig. 10B, is preferably introduced in step 182 'to estimate the engine load value.

As previously described, the engine load value is calculated using the engine speed signal and the boost pressure signal immediately prior to performing a shift. While the method described above provides a more fully populated torque table, the data is still discrete. So it is currently preferred to continue using a linear interpolation step, as indicated at step 184 ', to calculate the engine load value if the engine speed and boost pressure values do not exactly match the data available in the memory. In addition, the interpolation step 184 'enables the application of the more fully occupied 3-D torque table, without large memory requirements in the controller 12 for data storage by reducing the amount of data stored in the memory, to discrete engine speeds. For example, the data table may include data for engine speeds of 2400, 2200, 2000, 1800, and 1600 rpm, which include approximately 155 data points for each engine speed with 30 to 40 data points in the range of the maximum torque.

The interpolation routine indicated in step 184 'would be carried out as follows for an engine operating at 40 kPa boost pressure value and 2300 rpm. The controller 12 receives an engine load value for 40 kPa boost pressure / 2200 rpm and 40 kPa boost pressure / 2400 rpm from the panel lookup function, and then calculates the weighted average to estimate the engine load value for 40 kPa / 2300 rpm. If the engine is operating outside the data table area (ie, less than 1600 rpm or more than 2400 rpm), the torque table limits are used to estimate the engine load value.

While the boost pressure processing routine as illustrated in Figure 9A has been described with particular reference to the use of the 3-D torque map data technique in the context of the table lookup and interpolation functions, those skilled in the art should be aware that any method involving engine load as a function of engine speed and boost pressure could be used. For example, higher (second or larger) order nonlinear curve fitting techniques could be used to obtain a mathematical representation of the data so as to eliminate the need to perform the various interpolation routines previously described.

Referring to FIGS. 11A and 11B, the 7 designated shift control routine at step 116 shown in FIG. Will now be described in more detail. Referring first to step 186 in FIG. 11A, it is checked whether the output turn-on diagnosis has been performed. This diagnosis includes that the micro processor briefly turns on the solenoid valves, each individually, to ensure that there are no shorted control lines leading to the solenoid valve coils. It should be noted that loading one solenoid valve at a time in the Funk 9400 series transmission does not initiate a shift.

In step 188, the solenoid valves are actually turned on, each at a time, with appropriate driver signals from the microprocessor 12 if the initial turn-on diagnosis was not previously performed. With continued reference to FIG. 11A, in step 190, the power shift ratio is determined by dividing the measured output shaft speed by the measured input shaft speed. At step 192, a speed-over-ground alignment routine is performed to avoid damage to the directional clutches by automatically requesting an appropriate gear ratio for the measured input and output shaft speeds. For example, the controller 12 requests when the operator has depressed the clutch or out of gear, e.g. B. bang 18F has shifted to idle to prepare for an incoming stop signal, gradually and successively downshifting the transmission to a gear ratio that corresponds to the measured input and output shaft speeds. Thus, if a rolling stop is performed, downshifting to a gear corresponding to the speed of the "rolling stop" is automatically requested, e.g. B. Gear 13 F. On the other hand, if a full stop is made, the downshift to gear 11 F is automatically requested.

In step 194 it is checked whether the transmission is idling. This is done by determining whether either the operator has fully depressed the clutch pedal 26 so that the clutch pedal position sensor b 27 indicating the same, or whether the shift lever has been turned 36 of the transmission 23 in the neutral position, as registered monitoring switch 28 of the idling becomes. If the transmission is determined to be idling, a shift timer is set to zero, an idle shift timer is set to zero and an idle timer is started, all of which is indicated as step 196. Subsequently, an idle subroutine is executed, as indicated at step 198, to bring the transmission 23 into idle.

Will continue with reference to FIG. 11A, if it is not determined that the transmission 23 is in idling, as checked in step 194, the idle switch timer is increased by one, the switching timer also increased by one and the idle timer to zero, as in Step 200 is indicated. This step essentially monitors how long the shift lever 36 has been out of the neutral position. At step 202 it is checked whether the current gear is idle and, if so, an idle shift is carried out, as indicated at step 204. If the current gear is not idle, it is checked whether the current gear corresponds to the requested gear, as indicated in step 206. In other words, it is checked whether the position of the shift lever 36 continues to indicate the same transmission ratio as that in which the transmission is located. If the result of the test is yes, the system checks whether the solenoids that should be on to keep the transmission in the desired gear ratio are actually on and whether the solenoids that should be off are actually off, such as is indicated at step 208.

Is Referring further to FIG. 11A, if the test the result is false found at step 206, checks whether the switching operation which has been requested by the operator, resulting either from a forward gear into another forward gear or a reverse gear in a different reverse gear, as indicated at step 210. If this test returns no, it is determined that a shift to idle has been requested and the idle shift subroutine is executed, as indicated at step 212. It will be appreciated that this is the same idle shift subroutine that would have been requested in step 198 if it had been determined in step 194 that the transmission is in idle.

If the test at step 210 indicates that either a shift from one forward gear to another or a shift from one reverse gear to another reverse gear has been requested, a check is made to see if the requested shift is already in progress, as indicated at step 214. If so, the microprocessor 12 determines the appropriate PWM duty cycle and the appropriate solenoid actuation switching patterns based on how far control has advanced in performing the shift, all of which is indicated at step 212. Subsequently, at step 214, the fine clutch pedal sensor 26 is checked by the microprocessor 12 and if the pedal is pressed by the operator, the micro 22197 00070 552 001000280000000200012000285912208600040 0002019622233 00004 22078 processor 12 uses the signal generated by the sensor 26 to overwrite the PWM driver signal which would normally be used to engage the directional clutch involved to complete the shift. Thus, the operator always has the option of overriding the control signal which would act on the directional clutch involved, if conditions exist under which an even slower or faster clutch engagement is desired than would otherwise be requested by the microprocessor 12 .

Referring again to step 214, if determined If there is no switching operation in progress, the switching timer opens Set to zero, as indicated in step 218, and that appropriate PWM driver signal based on the compensated Boost pressure value determined, as indicated in step 220, what is called the arithmetic shifting profile routine.

Scaling of the boost pressure

In Fig. 12 is executed 11, the loading pressure shift sequence profile routine at step 220 shown in Fig., Shown in more detail. The boost pressure profile is based in part on the percentage of full load or the percentage load under which the engine is operating, as calculated in step 222. When boost pressure processing routine 148 is used to estimate engine load, the percentage load is divided by the equation (3) below as the difference between the conditioned boost pressure value (T _cond ) and the normalized boost pressure value at zero load (T _no-load ) the difference between the normalized boost pressure value at full load (T _full-load ) and the normalized boost pressure value at zero load (T _no-load ) is calculated.

When the boost pressure processing routine 148 'is used to estimate the engine load, the percent load is calculated according to equation (4) below as a ratio of the engine load value and the maximum engine torque.

Alternatively, the data tables from which the estimated engine load is calculated can be directly scaled to give an estimated percentage load rather than an estimated engine load. Thus, the microprocessor 12 can determine what percentage of the full load is on the engine when a shift is requested.

Still referring to Fig. 12 is checked at step 224 whether the idle switch timer value is greater than about 1.5 seconds. Through this check, the microprocessor 12 determines that the transmission has been idle for at least a predetermined time. If the result of this test is yes, it is determined that the transmission has not yet been shifted out of idle and that any load on the engine is due to a static tensile load (ie no dynamic load). If the test returns no, it is assumed that the vehicle is accelerating from a standstill and that the load on the engine is simply the load that is applied when the vehicle is brought up to the desired speed. In this case, as indicated at step 226, controller 12 will use a modified percentage load that is half the percentage load calculated at step 222.

Referring still to FIG. 12, at step 228, based on either the percentage load as calculated at step 222 or the modified value as determined at step 226, the desired time value within which the shift is to be performed is determined . This is done by the following equation (5):

Shift sequence profile = t _no-load + percentage load _* (t _full-load -t _no-load ) (5)

in which
t _no-load the _no-load period and
t _{full-load is} the full-load period.

In step 230, the appropriate work cycle for the PWM driver signal set. The determination is made according to the following equation (6):

Duty cycle = D / C _no-load + percentage load _* (D / C _full-load -D / C _no-load ) (6)

in which
D / C _no-load the _no-load duty cycle and
D / C _{full-load is} the full load duty cycle.

The calculation at step 230 determines which duty cycle is required to within the directional clutch to be closed the period specified in step 228 in full Bring intervention. Together, steps 228 and 230 determine the appropriate percentage of full load pressure and Full-load time value that is necessarily used to do that PWM driver signal for engaging the close the directional clutch in coordination with that on the motor acting load, as compensated by the boost pressure value or the engine load value is displayed. So be if the percentage load is 50% of a full load condition corresponds to 50% of the full load pressure and the full load time  value used to generate the PWM driver signal.

From the plots shown in FIGS. 14 and 15 it can be seen how the directional clutch to be closed is brought into engagement more quickly at higher engine loads. The upper plot in Fig. 15 gives the pressure on the opening clutch F1 over time during a shift from gear 9 F to gear 10 F in the form of curve 232 a and a shift from gear 10 F to gear 9 F in the form of a Curve 232 b again. The lower curve 234 indicates the pressure which is used to actuate the directional clutch F2 when this clutch closes during a shift from gear 9 F to gear 10 F, which is referred to as curve section 234 a. Section 234 b of this curve shows the rapid drop in pressure on the directional clutch F2 to be opened when a shift operation from gear 10 F to gear 9 F is carried out. The plots of FIG. 14 represent the behavior of the directional clutches F1 and F2 for an engine of the vehicle that operates at approximately 2520 rpm under no-load conditions.

In Fig. 15, the pressure curve for which is shown that open-way clutch F1 by the curve 236 and the force acting on closing pressure clutch F2 by the waveform 228th In the plots of Fig. 15, the engine speed is 2400 r / min, wherein the engine is fully loaded. Section 236 a of curve shape 236 and section 238 a of curve shape 238 indicate the pressure acting on the two directional clutches during a shift from gear 9 F to gear 10 F. Accordingly, section 236 b of curve 236 and section 238 b of curve 238 indicate the pressure acting on directional clutches F1 and F2 during a shift from gear 10 F to gear 9 F.

When comparing section 234a of curve 234 of FIG. 14 with section 238a of curve 238 of FIG. 15, it can be seen that the pressure used to drive the closing directional clutch is ramped up at a higher rate when the engine load increases and the engine speed has decreased. This also becomes clear when comparing section 232 b of curve 232 with section 236 b of curve 236 . In this case, clutch F1 is the directional clutch to be closed. It can be seen that the clutch F1 comes much faster (ie with a higher engagement rate) when the engine is loaded than when the engine is operating under zero load.

With reference to FIG. 13, the boost pressure calibration subroutine, which is requested in step 144 according to FIG. 9 and which is shown in a simplified form in FIG. 3, will now be described in more detail. It is initially checked whether the transmission is in gear 9 F, as indicated in step 240. If no, the boost pressure calibration mode is exited and, as indicated at step 242, the previous boost pressure calibration value is used for the subsequent determination of the appropriate PWM duty cycle based on the previously determined boost pressure signal. If the test at step 240 gives the result yes, it is checked whether the boost pressure calibration is already being carried out, as indicated at step 244. If this test gives the result of no, it is checked whether a boost pressure calibration switch on the input panel within the vehicle has been pressed by the operator, as indicated at step 246. If this test gives the result yes, a charge pressure calibration timer is set to zero, as indicated at step 248, and the routine ends at step 264.

If the test at step 246 returns no (ie, the boost pressure calibration switch has not been pressed), then the boost pressure calibration mode is exited at step 242. If the test at step 244 gives the result yes, then it is checked whether the clutch pedal position corresponds to more than 90% engagement, as indicated in step 250. If this test returns no, then the microprocessor 12 determines that the clutch pedal is currently being operated by the operator and the boost pressure calibration mode is exited. If, however, the test at step 250 gives the result yes, then it is checked whether the engine speed is greater than approximately 2250 rpm, as indicated in step 252. If this test gives the result no, then the microprocessor 12 determines that the engine is not at full throttle and again the boost pressure calibration mode is exited. However, if the test returns yes, step 254 tests whether the vehicle speed is greater than about 4.5 mph. This test ensures that the vehicle moves at least with a minimum predetermined speed that should be achieved under no-load conditions, if it is located in the passage 9 F. If this test returns no, then the microprocessor 12 determines that the calibration cannot be performed precisely and exits the boost pressure calibration mode. If the test returns yes, then the wastegate calibration timer is incremented by 12 ms as indicated at step 256, and it is then checked at step 258 if three seconds have passed since the wastegate calibration mode was started. If no, subtracting the determined current boost pressure value from the baseline boost pressure value under zero load conditions determines a boost pressure value, as indicated in step 260. If the test at step 258 returns yes, then the last markup value determined at step 260 is stored in RAM 16 of microprocessor 12 at step 162. The boost pressure calibration routine is then terminated, as indicated at step 264.

The preferred methods of the present invention are also applied during upshifts and downshifts between forward gears 10 F through 18 F, as will now be explained with reference to FIGS. 16 through 19. Initially, a calibration procedure is performed which corresponds in form to that shown in Fig. 2 by an appropriate percentage reduction in pressure on the directional clutch F2 when shifting up or down between gears 10 F and 18 F from one gear to another the vehicle is under zero load and to determine an appropriate percentage reduction in pressure on clutch F2 when the vehicle is under full load when shifting up or down between gears 10 F to 18 F. Accordingly, a percentage reduction in pressure acting on clutch F2 is determined for both no-load and full-load conditions, along with an appropriate time value, within which the clutch F2 pressure is ramped up by the Bring clutch F2 fully into engagement. The currently preferred value for reducing the pressure on clutch F2 during the upshift and downshift between gears 10 F to 18 F under zero load is approximately 80%. In other words, the pressure on clutch F2 is preferably reduced by about 80% if somehow shifting up or down between gears 10 F to 18 F.

In Fig. 16, a curve 266 indicates the pressure on the directional clutch F2 during an upshift between gears 10 F and 11 F again. As can be seen from section 266 a of curve shape 266 , the pressure on clutch F2 drops very quickly (almost instantaneously) by approximately 80% in order to disengage clutch F2 almost completely during the upshift. This amount of pressure reduction is sufficient in any case to interrupt the transmission of torque to the output shaft of the transmission. As can be seen from section 266 b, the pressure is then raised again in coordination with the percentage load (the corresponding procedure was described in connection with FIG. 12). The percentage load determines the duty cycle for the PWM driver signal that acts on clutch F2 and the period in which clutch F2 is fully engaged again. As indicated by section 266c of curve shape 266 , after a time which is represented by time period 266d , full pressure is subsequently applied to clutch F2. In this way, the methods described here are used not only to control clutches F1 and F2 during gear changes between gears 9 F and 10 F, but also during upshifts between gears between 10 F and 18 F.

In Fig. 17 an upshift between the gears 17 F and 18 F is shown. In Fig. 17, the pressure on the clutch F2 is represented by the curve 268th Again, the pressure on clutch F2 is reduced by about 80%, as indicated by section 268 a of curve 268 , to disengage clutch F2 almost completely during upshifting. The pressure on clutch F2 is then increased, as indicated by section 268 b of curve shape 268 , until full pressure acts on clutch F2 again, which is indicated in section 268 c of curve shape 268 . It can be seen that the time period, which is referred to as period 268 d, is longer than when shifting up between gears 10 F and 11 F. This is because the determined boost pressure is higher when the vehicle is shifting up from gear 17 F to gear 18 F speed suitable than at a speed at which a switching operation from gear 10 F to gear 11 F takes place, provided that all other factors remain the same. Furthermore, the speed difference in vehicle speeds that occurs between gears 17 F and 18 F is greater than that that occurs between gears 10 F and 11 F. So it is desirable if a longer period of time runs from the time at which the pressure on the clutch F2 is reduced by approximately 80% to the time at which the full pressure is again applied. In the preferred embodiment, a period of approximately 5 seconds from the pressure ramp-up to full pressure was determined under no load conditions in order to achieve very satisfactory results. By satisfactory it is meant that the shifting operation is accomplished by actuating clutch F2 until it is fully engaged at a rate and within a period of time which result in a relatively smooth shifting operation and which avoid undesirable jerking or jerking of the vehicle. Accordingly, the pressure on clutch F2 is increased much more slowly during an upshift between gears 17 F and 18 F than between gears 10 F and 11 F.

In FIG. 18, the pressure acting on clutch F2 during a downshift from gear 11 F to gear 10 F is shown as curve profile 240 . It should be noted that the clutch pressure indicated by curve 270 is under no load conditions. Section 270a shows a reduction in the pressure acting on clutch F2 by approximately 80% in order to disengage clutch F2 almost completely almost instantaneously. Section 270 b describes the increase in pressure according to the PWM duty cycle and the period of time, which are determined by the percentage load, until the full pressure acts on clutch F2 again, as indicated in section 270 c of curve shape 270 . The time period represented by section 270 d represents the total time that passes until the pressure on clutch F2 is again at full pressure.

In Fig. 19, the pressure on the clutch F2 during a downshift from gear 18 F to gear 17 F under zero load conditions is graphically represented by the curve 272 Darge. Section 272 a indicates a drop of approximately 80% in pressure on clutch F2 at the beginning of the downshift. Subsequently, the pressure on the clutch F2 will drive hochge, as indicated by the portion 272 b of the curve is indicated 272, to bring the pressure to the clutch F2 back to the full pressure is indicated by the area c as 272nd The time period indicated by section 272d is greater than when shifting down from gear 11 F to gear 10 F. This is again due to the fact that at vehicle operating speeds during a shift between gears 18 F and 17 F below zero -Load conditions generated boost pressure is greater than the boost pressure generated during a shift between gears 11 F and 10 F under no-load conditions.

Accordingly, from the plots of Fig. 16 to 19 ent detachable, that the directional clutch F2 to achieve conditions to a soft switching operation under no load-Be according to a suitable duty cycle and is brought within a suitable period of time engaged. If the high switching operations of FIGS. 16 and 17 load conditions full would have been carried out by operating under, the portions 266 a and 268 a of the curve 266 or 268 would be considerably shorter and would a drop in the pressure acting on the clutch F2 pressure by a very small amount, preferably between 0 and 10%. Likewise, sections 266b and 268b would , if the shifting operations were carried out under full load conditions, be steeper to significantly shorten the periods 266d and 268d, respectively, so that clutch F2 would return to full pressure much more quickly bring. If the percentage load indicates a load condition at a point midway between zero load and full-load, then would the waste and the pressure, as they are in the portions 266 a and displayed 268 a of the curve 266 or 268, a pressure drop of Show pressure on clutch F2 of only about 40%. Further, the time periods would be represented by the portions 270 b and 272 b of the waveform are shown 270 and 272, respectively, steeper under full load, a faster increase in the rate of display on the clutch F2 einwir kenden pressure. It is clear to the person skilled in the art that the teaching which has been presented here in connection with the control of the directional clutch F2 could just as easily be applied to the clutch F1 during an upshift and downshift between the gears 1 F to 9 F.

Claims (22)

1. A method for controlling a powershift transmission for an off-road vehicle, the powershift transmission having at least one proportionally controllable clutch connected to an engine, and the engine having a turbocharger and operating at an engine speed, comprising the steps:
Monitoring a boost pressure developed by the turbocharger and generating a boost pressure signal;
Monitoring the engine speed and generating an engine speed signal;
Determining an engine load as a function of the boost pressure signal and the engine speed signal and generating an engine load value;
Generating a switching profile signal depending on the engine load value and
Transmitting the shift profile signal to the proportional clutch to control the engagement of the clutch when shifting the powershift transmission. 2. The method according to claim 1, characterized in that the step of determining the engine load comprises the steps
Generating a data table that represents a known engine load as a function of a known engine speed and a known boost pressure for a plurality of operating conditions, and
Compare the boost pressure signal and the engine speed signal with the data table to determine the engine load value. 3. The method according to claim 3, characterized in that the Step of comparing the boost pressure signal and the engine speed range with the data table continues to include linear interpolation of the motor load value from the data panel, the boost pressure signal and the engine speed signal. 4. The method according to claim 2 or 3, characterized in that the step of generating the data table comprises:
Determining operating conditions for the engine, including throttle position, load condition, and engine speed;
Measuring boost pressure, engine speed and engine load measurements to determine the known boost pressure, engine speed, and engine load for the operating condition; and
Storage of the known boost pressure, the known engine speed and the known engine load as a data point in the data table to produce a thinly populated data table. 5. The method according to claim 4, characterized in that the step of generating the data table further comprises the steps:
Estimating approximate values between the measured values of at least two data points in the data table and
Store the approximate values as data points in the data table to create a more fully populated data table. 6. The method according to claim 5, characterized in that the step of estimating approximate values comprises the step:
Perform a least squares regression for each individual set of four adjacent data points. 7. The method according to claim 5 or 6, characterized in that the step of generating the data table further comprises the step:
Smooth the data points of the more fully populated data table. 8. The method according to any one of claims 5 to 7, characterized in that the step of generating the data table further comprises the step:
Select data points from the fully populated data table on discrete engine speeds. 9. The method according to any one of claims 1 to 8, characterized in that the step of generating a switching profile signal further comprises the steps:
Determining a percentage load from the engine load value and generating a weighted switching profile signal depending on the percentage load, a zero-load switching profile and a full-load switching profile. 10. The method according to claim 9, characterized in that the step of determining the percentage load comprises the steps:
Determining a full load engine load value while the vehicle is operating at full throttle and under full load conditions, and
Compare the engine load value to the full load engine load value to determine the percentage load. 11. The method according to any one of claims 1 to 10, characterized in that the steps are further provided:
Determining a wastegate calibration constant;
Modifying the boost pressure signal taking into account the calibration constant to produce a normalized boost pressure signal, and
Using the normalized boost pressure signal and the engine speed signal to determine the engine load value. 12. A method for generating a data table with a known engine load, a known engine speed and a known boost pressure for a plurality of operating states and for use in shifting a powershift transmission of an off-road vehicle, the powershift transmission having at least one proportionally controllable clutch connected to an engine, and wherein the engine has a turbocharger and operates at an engine speed, with the steps:
Determining operating conditions for the engine, including throttle position, load condition, and engine speed;
Measuring boost pressure, engine speed and engine load measurements to determine the known boost pressure, engine speed, and engine load for the operating condition; and
Storage of the known boost pressure, the known engine speed and the known engine load as a data point in the data table to produce a thinly populated data table. 13. The method according to claim 12, characterized in that the steps are further provided:
Estimating approximate values between the measured values of at least two data points in the data table and storing the approximate values as data points in the data table to generate a more fully populated data table. 14. The method according to claim 13, characterized in that the step of estimating approximate values comprises the step:
Perform a least squares regression for each individual set of four adjacent data points. 15. The method according to claim 13 or 14, characterized in that the step of generating the data table further comprises the step:
Smooth the data points of the more fully populated data table. 16. The method according to any one of claims 5 to 7, characterized in that the step of generating the data table further comprises the step:
Select data points from the fully populated data table on discrete engine speeds. 17. Electronic circuit control for use in an off-road vehicle, the off-road vehicle having an engine with a turbocharger, a boost pressure sensor and an engine speed sensor and a powershift transmission with at least one clutch, the clutch being proportional to a signal for shifting the powershift transmission, and being electronic Circuit control has:
a boost pressure signal generator for generating a boost pressure signal from the boost pressure sensor;
an engine speed signal generator for generating an engine speed signal from the engine speed sensor;
Means for determining an engine load value as a function of the boost pressure signal and the engine speed signal and
a switching profile signal generator for generating a switching profile signal depending on the engine load value. 18. Electronic circuit control according to claim 17, characterized characterized in that a memory is also provided to to save a data table that is known as an engine load Function of a known engine speed and a known one Boost pressure for a variety of engine operating conditions represents the engine load value by comparing the load pressure signal and the engine speed signal with the data board is determined. 19. Electronic circuit control according to claim 18, characterized characterized in that the electronic circuit control such is designed to measure the engine load value by a linear Interpolation from the data table, the boost pressure signal and the Engine speed signal calculated. 20. Electronic circuit control according to one of the claim 17 to 19, characterized in that a load signal continues generator for generating a percentage load from the Motor load value is provided, the switching profile signal generator taking into account the percentage load, one Zero-load switching profile and a full-load switching profile weighted switching profile signal generated.   21. Powershift transmission with an electronic control system one of claims 17 to 20 and with at least one Proportionally controllable clutch, characterized in that the clutch has a controllable valve, the controllable valve for proportional control of the clutch in their intervention with a given intervention rate in response to the shift profile signal for shifting the powershift transmission serves. 22. Power shift transmission according to claim 22, characterized net that the clutch is a directional clutch.